This invention relates to a process for the production of a cyclic amidine.
A number of processes have thus far been proposed for the production of a cyclic amidine such as a 2-imidazoline compound. For example, JP-B-39-24965 discloses a process in which a nitrile is reacted with a diamine in the presence of sulfur for the production of a 2-imidazoline compound. This process has a problem because the process requires the removal of harmful hydrogen sulfide. JP-A-55-83753 suggests a vapor phase reaction, of a nitrile with a diamine. This process has a problem that specifically limited conditions and apparatuses are required and the yield of the amidine product is low. JP-A-59-84873 discloses a process in which a nitrile is reacted with a diamine in the presence of copper acetate monohydrate. This process has a problem because by-products are formed in a large amount. JP-A-3-163064 proposes the reaction of a nitrile or a carboxylic acid with a diamine in the presence of gamma-alumina or silica. This process requires a reaction temperature of as high as 300.degree. C. so that a specific reactor is required. Further, a large amount of by-products is unavoidably yielded. DE-A-2154948 discloses the reaction of oxazoline with ethylene diamine or 1,3-propanediamine for the production of an imidazoline or pyrimidin compound. The use of oxazoline as a raw material is, however, disadvantageous from the standpoint of economy. This process also has a problem because the yield is low.